-LRB- CNN -RRB- -- By distance , the running of the bulls course in Pamplona is pretty short : just 850 meters , or half a mile .

But with six , half-ton raging bulls and their menacing horns closing fast , the run can strangely seem like an eternity .

An eternity of thrills , of bravery and bragging rights , and sometimes , of tragedy .

The tradition of running bulls in this northern Spanish city dates back 400 years , and became known worldwide after author Ernest Hemingway wrote about it in his 1920s novel , `` The Sun Also Rises , '' also published under the title `` Fiesta . ''

Nowadays the annual San Fermin festival is so popular that Pamplona 's population of 200,000 can triple during the eight consecutive days of running , held from July 7 to 14 , at 8 a.m. daily .

Hordes of international travelers , many of them young , crowd in for a chance to watch from the barricades and balconies .

Many even try their luck with the bulls .

Some years ago , I was one of them .

I made my only run with the bulls and like most who take part , I did n't run very far .

The bulls are faster , and the runners -- now more than a thousand most days , and even more on weekends -- are densely packed .

No escape

I started close to the beginning of the course , near the top of the Cuesta de Santo Domingo , the hill leading up from the bull corrals , and then dashed across city hall plaza .

By the time I took cover , I could n't even get close to the supposed safety of the wooden barricade on my right , because there were already clumps of runners packed against it .

Luckily , the bulls kept going straight and did n't turn right , toward me , I kept thinking afterward .

Others went further that day , among them my Spanish friend Chema . Perhaps because he 's from a farming village and knows more about bulls .

But for novices and others who do n't know enough , there 's fresh help .

Just days ago , a group of American , British and Spanish bull running veterans published an e-book : `` Fiesta : How to Survive the Bulls of Pamplona . ''

Contributors include John Hemingway , grandson of the novelist and himself an author ; Jim Hollander , a Israel-based photographer for the European Pressphoto Agency who 's captured images of the running for years ; and Alexander Fiske-Harrison , a Briton who 's fought bulls .

Their collective advice goes well beyond the most important mantra -- that if you fall to the street while running -- stay down and do n't move , and the bulls will likely step over you .

I did n't know that rule when I ran .

It 's possible some others who in the past have been gored or even killed may not have known it , or heeded it . Because the instinct to get up from the street can come at the worst moment -- just as the bulls ' horns arrive .

There 've been 15 deaths since records began in 1924 , most recently in 2009 when a 27-year-old Spanish man was fatally gored in the neck .

Thousands more have been injured , often hurt when falling or being pushed to the ground by frantic runners .

On the first three days of running this year , 13 people have been taken to hospital , three for goring-related injuries and the rest having being hurt in falls or collisions .

Of these , three were non-Spanish , including a 32-year-old man from Chicago who was gored in the right thigh , a 23-year-old from Japan and a 23-year-old man from Nottingham .

Ambulances and medical teams now line the course , and the injured are usually transported quickly to hospitals staffed with surgeons experienced in operating on bull goring wounds .

Seeing red

Police typically try to make the running safer by limiting the crowds inside the course , and prohibiting those who are clearly drunk or carrying objects , like cameras .

Yet some see red at this spectacle .

This year , animal rights groups again plan demonstrations decrying the bull running and subsequent bullfights where the animals are killed , in the afternoon .

Campaigners have had success in Barcelona , where the Catalan regional parliament voted in 2010 to ban bullfights in that region , but their criticism does not seem to have dented Pamplona 's event .

The fiesta is an unrivaled source of revenue for the town , an intense week of tourism worth millions of dollars , and the bull running is just a small , albeit renowned , part .

Pamplona 's city hall says nearly 1.5 million people attended the hundreds of concerts , parades , children 's activities and religious events organized around last year 's celebration of the city 's patron saint .

Yet those eight days included just 17,813 bull runners , some of them repeat participants over several days .

Since my own , short run , I 've returned various times as a correspondent to cover Pamplona 's big event .

And one of my questions has brought an intriguing answer : some international revelers say they 've never read anything by Hemingway .

Not a single book , much less his novel that brought fame to this town .

They 've said it repeatedly , over the years , even in the shadow of the statue of Hemingway , which the town proudly erected outside the bullring .

For some , the details of his passionate writing are lost .

But they 've picked up the gist : Pamplona , they will tell me , is a must see : this wild fiesta and this dangerous bull running .

@highlight

Running of the Bulls begins this year on July 7 and is expected to attract thousands of participants

@highlight

The annual event usually results in scores of injuries and occasionally fatalities

@highlight

The Spanish fiesta was immortalized in print by Ernest Hemingway in his novel `` The Sun Also Rises . ''

@highlight

Hemingway 's grandson is among those who have produced an e-book on how to survive the bull runs